A mainshaft of a honing machine needs to perform reciprocating motion during honing process, thus numerical control technology for reciprocation of the mainshaft of a honing machine is core manufacturing technology of honing machines, which determines the performance of the honing machine as well as the level of honing process.
Currently, numerical control for reciprocation of the mainshaft has been achieved in advanced honing machines, there are two control drive methods of a reversing control system of a mainshaft hydraulic cylinder which performs reciprocation, in one way, the numerical control for reversing of the mainshaft is achieved through a control drive system with an electro-hydraulic position reversing closed-loop, which is composed of an electro-hydraulic servo proportional valve and a mainshaft displacement sensor; in the other way, a special rotary valve for honing is used, which converts reciprocating linear motion of the mainshaft to rotary motion of a control unit inside the valve, a pilot control part of the valve is driven to rotate by a motor, such rotation of the pilot control part and the above described rotation converted from the reciprocation of the mainshaft constitute a rotary mechanical-hydraulic position closed-loop via a special mechanism, and then the numerical control for reversing of the mainshaft is achieved by electrical interface of a rotary valve controller.
In above two reversing control systems of the mainshaft, for the control drive system with an electro-hydraulic position reversing closed-loop composed of an electro-hydraulic servo proportional valve and a mainshaft displacement sensor, the electro-hydraulic servo proportional valve is expensive and its requirement for working condition is harsh; on the other hand, for the reversing control system which adopts a special rotary valve for honing, linear motion of the mainshaft needs to be converted to rotary motion, and a complex system with a rotary mechanical-hydraulic position closed-loop is adopted, thus not only greatly increasing the production cost of the reversing control system, but also making commissioning and maintenance of such a system very complicated.